Revision of Leucothoe (Amphipoda, Crustacea) from the Southern Ocean: a cosmopolitanism concept is vanishing Author Krapp-Schickel, Traudl E1B1DCCF-04CB-4B1A-A69B-A7C25EC95A38 Zoologisches Forschungsmuseum A. Koenig, Adenauerallee 160, D- 53113 Bonn, Germany E-mail: traudl. krapp @ uni-bonn. de (corresponding author) & urn: lsid: zoobank. org: author: E 1 B 1 DCCF- 04 CB- 4 B 1 A-A 69 B-A 7 C 25 EC 95 A 38 Author Broyer, Claude De 970067BF-A792-48A9-B32A-B91F0E41C354 Royal Belgian Institute of Natural Sciences, rue Vautier 29, B- 1000 Bruxelles, Belgium E-mail: claude. debroyer @ naturalsciences. be & urn: lsid: zoobank. org: author: 970067 BF-A 792 - 48 A 9 - B 32 A-B 91 F 0 E 41 C 354 text European Journal of Taxonomy 2014 2014-04-15 80 1 55 journal article 21805 10.5852/ejt.2014.80 6758c39f-119f-401b-bf6e-c458ea4f4dca 2118-9773 3860901 FDB2386B-9DC8-47C3-B7AB-406BE4264478 Leucothoe longimembris sp. nov. urn:lsid:zoobank.org:act: 935721E6-F9D5-4E0A-9AAD-5DEE628627EB Figs 5 , 8-10 Diagnosis A 1> A 2, eyes absent, Cx 1-5 all ending ventrally at about the same level. Basis P 5-7 slim, broadest not medially but proximally; both margins of bases weakly serrated. Ep 2, 3 posterodistal corner lengthened and pointed. U 1 rami subequal, U 2 rami unequal, ratio 2:1, U 3 rami subequal, about 2/3 of peduncle. Etymology Many articles (in Latin membrum , abl. plural membris ) like antennae, Gn 1, but especially the bases of the peraeopods 5-7 are unusually elongated (= longis ) and this character is different from all other species hitherto known from the Antarctic or sub-Antarctic regions. The chosen specific name is used as non-flexible apposition. Type material Holotype ♀ ov. 15 mm ( RBINS , I.G. 32565 / INV. 103462), Polarstern ANT XXII-3 ( ANDEEP 3 ); sta. PS67/74-6 EBS; 20 Feb. 2005 ; eastern Weddell Sea ; 71°18.35’S , 13°57.71’W ; 1030 m ; epibenthic sledge; coll. C. De Broyer & B. Danis. Description Length 15 mm . Head Anterior margin rounded, anterodistal margin rectangular with rounded corner. Mid-cephalic keel not prominent. Rostrum small. Eyes absent. Antenna 1 nearly half of body length, flagellum with 21 articles, peduncle art. 1 width proximally less than twice article 2, disto-inferiorly with acute tooth, length art. 1 subequal to art. 2, art. 3 about 1/4 of art. 2, acc. flagellum not seen. Peduncle art. 3 + flagellum shorter than peduncle arts 1+2. Antenna 2 shorter than antenna 1, peduncle art. 4> art. 5, flagellum 7 arts. Mouthparts: Mandibles lacking molars, incisor and lacinia mobilis dentate; palp 3-articulate, art. 2 with many lateral setae of different length, art. 3 with 2 distal setae, more than half length of art. 2. Maxilliped IP small, fused, OP reaching about 1/5 of inner margin of palp art. 1; palp articles similar in length. Peraeon Cx 1 smooth, length> width; anterior margin smooth, facial setae absent, inferior margin smooth. Gn 1 basis slender, not inflated, both margins with short setae; ischium smooth; carpus basis about half as long as propodus, distal part linear and extremely narrow, about 10 x longer than wide; propodus straight, about 6 x as long as wide, palm with short setae; dactylus smooth, reaching about 1/3 propodus length. Cx 2 subquadrangular, about as long as wide, twice as wide as Cx 3, distally smooth; anterior margin and anterodistal corner regularly rounded, inferior margin straight, posteriorly somewhat excavated, facial setae absent. Fig. 8. Leucothoe longimembris sp. nov. , holotype ♀ 15 mm. A 1, 2 = antenna 1, 2; UL = upper lip; Mx 1, 2 = maxilla 1, 2; Md, Md’ = mandible from both sides; Mxp = maxilliped. Fig. 9. Leucothoe longimembris sp. nov. , holotype ♀ 15 mm. Cx 1-4 = coxa 1-4; Gn 1, 2 = gnathopod 1, 2; P 3, 4 = peraeopod 3, 4. Fig. 10. Leucothoe longimembris sp. nov. , holotype ♀ 15 mm. Cx 5-7 = coxa 5-7; P 5-7 = peraeopod 5-7; Ep 1-3 = epimeral plate 1-3; U 1, U 3 = uropod 1, 3; T = telson; T’ = telson distally enlarged. Gn 2 basis not inflated, on both margins short setae; carpus reaching about 1/3 propodus length, curved, distally serrated, setose; propodus anterodistally with short, acute prolongation, posterior margin with many low humps, palm convex, proximally near dactylus-end no corner; facial setae not seen; dactylus curved, both margins smooth, bare, reaching about 2/3 of propodus length. Cx 3 elongate, length> width, anterior margin rounded, posterior margin straight, distally rounded, smooth, facial setae absent. Cx 4 length shorter than width, smooth, bare, anterior margin nearly straight, distal margin rounded, posterior margin shorter than anterior one, not excavate, facial setae absent. P 3, 4 basis very narrow, wider than delicate merus; dactylus reaching nearly half length of propodus, all margins naked. Cx 5-7 facial setae absent. P 5-7 similar, bases length:width ratio about 2.5 (P 5), 2.3 (P 6) and 2.6 (P 7), both margins with very slight serrations. Merus in P 5-7 with posterodistal corner lengthened. Pleon Ep 1-3 bare. Ep 1 distally rounded, Ep 2, 3 posteroventral corner acutely upturned. Uropods: U 2 the shortest, with very unequal rami (ratio about 1:2), the shorter one shorter than peduncle. U 1 and U 3 with subequal rami. Telson ratio l:w = 3, tip five-dentate because of four indentations near distal end. Remarks The new blind species is similar to the (also blind) deep-sea species L. ayrtonia Bellan-Santini, 1997 ( 5 mm ) and L. atosi Bellan-Santini, 2007 ( 12 mm ), found in the Mid-Atlantic Ridge at 37°N , 31°W at a depth of 850 m , and at the Barbados Trench, 10°N , 58°W at a depth of 1947 m respectively. Differences from L. ayrtonia are in the large rostrum, Cx 4 with posterodistal acute corner, Ep 3 quadrate with small tooth, from L. atosi are in much shorter antennae, blunt posterodistal corner at Ep 2, less unequal U 2 and broader telson. Also L. ushakovi Gurjanova, 1951 ( type from Greenland at a depth of 3892 m , specimens from 8-34 mm length; see Krapp-Schickel & Vader 2012 ) has P 5-7 bases not medially, but proximally widest and is blind; differences with L. longimembris are are the setose bases of Gn 1, 2 and very unequal rami in U 2 in the here described material (vs. naked bases and less unequal rami in L. ushakovi ), a longer Gn 1 dactylus and a five-dentate slender telson here (vs. short dactylus and threedentate broader telson in L. ushakovi ).